FairEmail/app/src/main/java/eu/faircode/email/ConnectionHelper.java

779 lines
30 KiB
Java

package eu.faircode.email;
/*
This file is part of FairEmail.
FairEmail is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
FairEmail is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FairEmail. If not, see <http://www.gnu.org/licenses/>.
Copyright 2018-2022 by Marcel Bokhorst (M66B)
*/
import android.accounts.AccountsException;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkInfo;
import android.os.Build;
import android.provider.Settings;
import android.telephony.TelephonyManager;
import androidx.annotation.Nullable;
import androidx.preference.PreferenceManager;
import com.sun.mail.iap.ConnectionException;
import com.sun.mail.util.FolderClosedIOException;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.net.URL;
import java.net.URLDecoder;
import java.net.UnknownHostException;
import java.nio.charset.StandardCharsets;
import java.security.cert.Certificate;
import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Locale;
import java.util.Objects;
import javax.mail.MessagingException;
import javax.net.SocketFactory;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import inet.ipaddr.IPAddressString;
public class ConnectionHelper {
static final int MAX_REDIRECTS = 5; // https://www.freesoft.org/CIE/RFC/1945/46.htm
static final List<String> PREF_NETWORK = Collections.unmodifiableList(Arrays.asList(
"metered", "roaming", "rlah", "require_validated", "require_validated_captive", "vpn_only" // update network state
));
// Roam like at home
// https://en.wikipedia.org/wiki/European_Union_roaming_regulations
private static final List<String> RLAH_COUNTRY_CODES = Collections.unmodifiableList(Arrays.asList(
"AT", // Austria
"BE", // Belgium
"BG", // Bulgaria
"HR", // Croatia
"CY", // Cyprus
"CZ", // Czech Republic
"DK", // Denmark
"EE", // Estonia
"FI", // Finland
"FR", // France
"DE", // Germany
"GR", // Greece
"HU", // Hungary
"IS", // Iceland
"IE", // Ireland
"IT", // Italy
"LV", // Latvia
"LI", // Liechtenstein
"LT", // Lithuania
"LU", // Luxembourg
"MT", // Malta
"NL", // Netherlands
"NO", // Norway
"PL", // Poland
"PT", // Portugal
"RE", // La Réunion
"RO", // Romania
"SK", // Slovakia
"SI", // Slovenia
"ES", // Spain
"SE" // Sweden
));
static {
System.loadLibrary("fairemail");
}
public static native int jni_socket_keep_alive(int fd, int seconds);
public static native int jni_socket_get_send_buffer(int fd);
public static native boolean jni_is_numeric_address(String _ip);
static class NetworkState {
private Boolean connected = null;
private Boolean suitable = null;
private Boolean unmetered = null;
private Boolean roaming = null;
private Network active = null;
boolean isConnected() {
return (connected != null && connected);
}
boolean isSuitable() {
return (suitable != null && suitable);
}
boolean isUnmetered() {
return (unmetered != null && unmetered);
}
boolean isRoaming() {
return (roaming != null && roaming);
}
Network getActive() {
return active;
}
public void update(NetworkState newState) {
connected = newState.connected;
suitable = newState.suitable;
unmetered = newState.unmetered;
roaming = newState.roaming;
active = newState.active;
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj instanceof NetworkState) {
NetworkState other = (NetworkState) obj;
return (Objects.equals(this.connected, other.connected) &&
Objects.equals(this.suitable, other.suitable) &&
Objects.equals(this.unmetered, other.unmetered) &&
Objects.equals(this.roaming, other.roaming) &&
Objects.equals(this.active, other.active));
} else
return false;
}
@Override
public String toString() {
return "connected=" + connected +
" suitable=" + suitable +
" unmetered=" + unmetered +
" roaming=" + roaming +
" active=" + active;
}
}
static boolean isConnected(Context context, Network network) {
NetworkInfo ni = getNetworkInfo(context, network);
return (ni != null && ni.isConnected());
}
static NetworkInfo getNetworkInfo(Context context, Network network) {
try {
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
return (cm == null ? null : cm.getNetworkInfo(network));
} catch (Throwable ex) {
Log.e(ex);
return null;
}
}
static NetworkState getNetworkState(Context context) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean metered = prefs.getBoolean("metered", true);
boolean roaming = prefs.getBoolean("roaming", true);
boolean rlah = prefs.getBoolean("rlah", true);
NetworkState state = new NetworkState();
try {
Boolean isMetered = isMetered(context);
state.connected = (isMetered != null);
state.unmetered = (isMetered != null && !isMetered);
state.suitable = (isMetered != null && (metered || !isMetered));
state.active = getActiveNetwork(context);
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (state.connected && !roaming) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
NetworkInfo ani = (cm == null ? null : cm.getActiveNetworkInfo());
if (ani != null)
state.roaming = ani.isRoaming();
} else {
Network active = (cm == null ? null : cm.getActiveNetwork());
if (active != null) {
NetworkCapabilities caps = cm.getNetworkCapabilities(active);
if (caps != null)
state.roaming = !caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING);
}
}
if (state.roaming != null && state.roaming && rlah)
try {
TelephonyManager tm = Helper.getSystemService(context, TelephonyManager.class);
if (tm != null) {
String sim = tm.getSimCountryIso();
String network = tm.getNetworkCountryIso();
Log.i("Country SIM=" + sim + " network=" + network);
if (sim != null && network != null &&
RLAH_COUNTRY_CODES.contains(sim.toUpperCase()) &&
RLAH_COUNTRY_CODES.contains(network.toUpperCase()))
state.roaming = false;
}
} catch (Throwable ex) {
Log.w(ex);
}
}
} catch (Throwable ex) {
Log.e(ex);
}
return state;
}
private static Boolean isMetered(Context context) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean standalone_vpn = prefs.getBoolean("standalone_vpn", false);
boolean require_validated = prefs.getBoolean("require_validated", false);
boolean require_validated_captive = prefs.getBoolean("require_validated_captive", true);
boolean vpn_only = prefs.getBoolean("vpn_only", false);
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null) {
Log.i("isMetered: no connectivity manager");
return null;
}
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
NetworkInfo ani = cm.getActiveNetworkInfo();
if (ani == null || !ani.isConnected())
return null;
if (vpn_only && !vpnActive(context))
return null;
return cm.isActiveNetworkMetered();
}
Network active = cm.getActiveNetwork();
if (active == null) {
Log.i("isMetered: no active network");
return null;
}
// onLost [... state: SUSPENDED/SUSPENDED ... available: true]
// onLost [... state: DISCONNECTED/DISCONNECTED ... available: true]
NetworkInfo ani = cm.getNetworkInfo(active);
if (ani == null || ani.getState() != NetworkInfo.State.CONNECTED) {
Log.i("isMetered: no/connected active info ani=" + ani);
if (ani == null ||
ani.getState() != NetworkInfo.State.SUSPENDED ||
ani.getType() != ConnectivityManager.TYPE_VPN)
return null;
}
NetworkCapabilities caps = cm.getNetworkCapabilities(active);
if (caps == null) {
Log.i("isMetered: active no caps");
return null; // network unknown
}
Log.i("isMetered: active caps=" + caps);
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
Log.i("isMetered: no internet");
return null;
}
boolean captive = caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_CAPTIVE_PORTAL);
if ((require_validated || (require_validated_captive && captive)) &&
Build.VERSION.SDK_INT >= Build.VERSION_CODES.M &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)) {
Log.i("isMetered: not validated captive=" + captive);
return null;
}
}
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)) {
Log.i("isMetered: active restricted");
return null;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_FOREGROUND)) {
Log.i("isMetered: active background");
return null;
}
if (vpn_only) {
boolean vpn = vpnActive(context);
Log.i("VPN only vpn=" + vpn);
if (!vpn)
return null;
}
if (standalone_vpn ||
caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
// NET_CAPABILITY_NOT_METERED is unreliable on older Android versions
boolean metered = cm.isActiveNetworkMetered();
Log.i("isMetered: active not VPN metered=" + metered);
return metered;
}
// VPN: evaluate underlying networks
Integer transport = null;
if (caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
transport = NetworkCapabilities.TRANSPORT_CELLULAR;
else if (caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))
transport = NetworkCapabilities.TRANSPORT_WIFI;
boolean underlying = false;
Network[] networks = cm.getAllNetworks();
for (Network network : networks) {
caps = cm.getNetworkCapabilities(network);
if (caps == null) {
Log.i("isMetered: no underlying caps");
continue; // network unknown
}
Log.i("isMetered: underlying caps=" + caps);
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
Log.i("isMetered: underlying no internet");
continue;
}
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)) {
Log.i("isMetered: underlying restricted");
continue;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_FOREGROUND)) {
Log.i("isMetered: underlying background");
continue;
}
if (!caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN) &&
(caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) ||
caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) &&
(transport != null && !caps.hasTransport(transport))) {
Log.i("isMetered: underlying other transport");
continue;
}
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
underlying = true;
Log.i("isMetered: underlying is connected");
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)) {
Log.i("isMetered: underlying is unmetered");
return false;
}
}
}
if (!underlying)
return null;
// Assume metered
Log.i("isMetered: underlying assume metered");
return true;
}
static Network getActiveNetwork(Context context) {
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null)
return null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
return cm.getActiveNetwork();
NetworkInfo ani = cm.getActiveNetworkInfo();
if (ani == null)
return null;
Network[] networks = cm.getAllNetworks();
for (Network network : networks) {
NetworkInfo ni = cm.getNetworkInfo(network);
if (ni == null)
continue;
if (ni.getType() == ani.getType() &&
ni.getSubtype() == ani.getSubtype())
return network;
}
return null;
}
static boolean isIoError(Throwable ex) {
if (ex instanceof MessagingException &&
ex.getMessage() != null &&
ex.getMessage().contains("Got bad greeting") &&
ex.getMessage().contains("[EOF]"))
return true;
while (ex != null) {
if (isMaxConnections(ex.getMessage()) ||
ex instanceof IOException ||
ex instanceof FolderClosedIOException ||
ex instanceof ConnectionException ||
ex instanceof AccountsException ||
ex instanceof InterruptedException ||
"EOF on socket".equals(ex.getMessage()) ||
"Read timed out".equals(ex.getMessage()) || // POP3
"failed to connect".equals(ex.getMessage()))
return true;
ex = ex.getCause();
}
return false;
}
static boolean isMaxConnections(Throwable ex) {
while (ex != null) {
if (isMaxConnections(ex.getMessage()))
return true;
ex = ex.getCause();
}
return false;
}
static boolean isMaxConnections(String message) {
return (message != null &&
(message.contains("Too many simultaneous connections") /* Gmail */ ||
message.contains("Maximum number of connections") /* ... from user+IP exceeded */ /* Dovecot */ ||
message.contains("Too many concurrent connections") /* ... to this mailbox */ ||
message.contains("User is authenticated but not connected") /* Outlook */ ||
message.contains("Account is temporarily unavailable") /* Arcor.de / TalkTalk.net */ ||
message.contains("Connection dropped by server?")));
}
static Boolean isSyntacticallyInvalid(Throwable ex) {
if (ex.getMessage() == null)
return false;
// 501 HELO requires valid address
// 501 Syntactically invalid HELO argument(s)
String message = ex.getMessage().toLowerCase(Locale.ROOT);
return message.contains("syntactically invalid") ||
message.contains("requires valid address");
}
static boolean isDataSaving(Context context) {
// https://developer.android.com/training/basics/network-ops/data-saver.html
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
return false;
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null)
return false;
// RESTRICT_BACKGROUND_STATUS_DISABLED: Data Saver is disabled.
// RESTRICT_BACKGROUND_STATUS_ENABLED: The user has enabled Data Saver for this app. (Globally)
// RESTRICT_BACKGROUND_STATUS_WHITELISTED: The user has enabled Data Saver but the app is allowed to bypass it.
int status = cm.getRestrictBackgroundStatus();
return (status == ConnectivityManager.RESTRICT_BACKGROUND_STATUS_ENABLED);
}
static String getDataSaving(Context context) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
return null;
try {
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null)
return null;
int status = cm.getRestrictBackgroundStatus();
switch (status) {
case ConnectivityManager.RESTRICT_BACKGROUND_STATUS_DISABLED:
return "disabled";
case ConnectivityManager.RESTRICT_BACKGROUND_STATUS_ENABLED:
return "enabled";
case ConnectivityManager.RESTRICT_BACKGROUND_STATUS_WHITELISTED:
return "whitelisted";
default:
return Integer.toString(status);
}
} catch (Throwable ex) {
Log.e(ex);
return null;
}
}
static boolean vpnActive(Context context) {
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null)
return false;
try {
for (Network network : cm.getAllNetworks()) {
NetworkCapabilities caps = cm.getNetworkCapabilities(network);
if (caps != null && caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN))
return true;
}
} catch (Throwable ex) {
Log.w(ex);
}
return false;
}
static boolean airplaneMode(Context context) {
try {
return (Settings.Global.getInt(context.getContentResolver(),
Settings.Global.AIRPLANE_MODE_ON, 0) != 0);
} catch (Throwable ex) {
Log.e(ex);
return false;
}
}
static InetAddress from6to4(InetAddress addr) {
// https://en.wikipedia.org/wiki/6to4
if (addr instanceof Inet6Address) {
byte[] octets = ((Inet6Address) addr).getAddress();
if (octets[0] == 0x20 && octets[1] == 0x02)
try {
return Inet4Address.getByAddress(Arrays.copyOfRange(octets, 2, 6));
} catch (Throwable ex) {
Log.e(ex);
}
}
return addr;
}
static boolean isNumericAddress(String host) {
// IPv4-mapped IPv6 can be 45 characters
if (host == null || host.length() > 64)
return false;
return ConnectionHelper.jni_is_numeric_address(host);
}
static boolean isLocalAddress(String host) {
try {
InetAddress addr = ConnectionHelper.from6to4(InetAddress.getByName(host));
return (addr.isLoopbackAddress() ||
addr.isSiteLocalAddress() ||
addr.isLinkLocalAddress());
} catch (UnknownHostException ex) {
Log.e(ex);
return false;
}
}
static boolean inSubnet(final String ip, final String net, final int prefix) {
try {
return new IPAddressString(net + "/" + prefix).getAddress()
.contains(new IPAddressString(ip).getAddress());
} catch (Throwable ex) {
Log.w(ex);
return false;
}
}
static boolean[] has46(Context context) {
boolean has4 = false;
boolean has6 = false;
try {
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces != null && interfaces.hasMoreElements()) {
NetworkInterface ni = interfaces.nextElement();
for (InterfaceAddress iaddr : ni.getInterfaceAddresses()) {
InetAddress addr = iaddr.getAddress();
boolean local = (addr.isLoopbackAddress() || addr.isLinkLocalAddress());
EntityLog.log(context, EntityLog.Type.Network,
"Interface=" + ni + " addr=" + addr + " local=" + local);
if (!local)
if (addr instanceof Inet4Address)
has4 = true;
else if (addr instanceof Inet6Address)
has6 = true;
}
}
} catch (Throwable ex) {
Log.e(ex);
/*
java.lang.NullPointerException: Attempt to read from field 'java.util.List java.net.NetworkInterface.childs' on a null object reference
at java.net.NetworkInterface.getAll(NetworkInterface.java:498)
at java.net.NetworkInterface.getNetworkInterfaces(NetworkInterface.java:398)
*/
}
return new boolean[]{has4, has6};
}
static List<String> getCommonNames(Context context, String domain, int port, int timeout) throws IOException {
List<String> result = new ArrayList<>();
InetSocketAddress address = new InetSocketAddress(domain, port);
SocketFactory factory = SSLSocketFactory.getDefault();
try (SSLSocket sslSocket = (SSLSocket) factory.createSocket()) {
EntityLog.log(context, EntityLog.Type.Network, "Connecting to " + address);
sslSocket.connect(address, timeout);
EntityLog.log(context, EntityLog.Type.Network, "Connected " + address);
sslSocket.setSoTimeout(timeout);
sslSocket.startHandshake();
Certificate[] certs = sslSocket.getSession().getPeerCertificates();
for (Certificate cert : certs)
if (cert instanceof X509Certificate) {
try {
result.addAll(EntityCertificate.getDnsNames((X509Certificate) cert));
} catch (CertificateParsingException ex) {
Log.w(ex);
}
}
}
return result;
}
static void setUserAgent(Context context, HttpURLConnection connection) {
connection.setRequestProperty("User-Agent", WebViewEx.getUserAgent(context));
if (BuildConfig.DEBUG) {
// https://web.dev/migrate-to-ua-ch/
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean generic_ua = prefs.getBoolean("generic_ua", false);
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA
connection.setRequestProperty("Sec-CH-UA", "\"Chromium\""); // No WebView API yet
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA-Mobile
connection.setRequestProperty("Sec-CH-UA-Mobile", "?1");
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA-Platform
connection.setRequestProperty("Sec-CH-UA-Platform", "\"Android\"");
if (!generic_ua) {
String release = Build.VERSION.RELEASE;
if (release == null)
release = "";
release = release.replace("\"", "'");
String model = Build.MODEL;
if (model == null)
model = "";
model = model.replace("\"", "'");
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA-Platform-Version
connection.setRequestProperty("Sec-CH-UA-Platform-Version", "\"" + release + "\"");
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA-Model
connection.setRequestProperty("Sec-CH-UA-Model", "\"" + model + "\"");
}
}
}
static HttpURLConnection openConnectionUnsafe(Context context, String source, int ctimeout, int rtimeout) throws IOException {
return openConnectionUnsafe(context, new URL(source), ctimeout, rtimeout);
}
static HttpURLConnection openConnectionUnsafe(Context context, URL url, int ctimeout, int rtimeout) throws IOException {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean open_safe = prefs.getBoolean("open_safe", false);
int redirects = 0;
while (true) {
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(false);
urlConnection.setReadTimeout(rtimeout);
urlConnection.setConnectTimeout(ctimeout);
urlConnection.setInstanceFollowRedirects(true);
if (urlConnection instanceof HttpsURLConnection) {
if (!open_safe)
((HttpsURLConnection) urlConnection).setHostnameVerifier(new HostnameVerifier() {
@Override
public boolean verify(String hostname, SSLSession session) {
return true;
}
});
} else {
if (open_safe)
throw new IOException("https required url=" + url);
}
ConnectionHelper.setUserAgent(context, urlConnection);
urlConnection.connect();
try {
int status = urlConnection.getResponseCode();
if (!open_safe &&
(status == HttpURLConnection.HTTP_MOVED_PERM ||
status == HttpURLConnection.HTTP_MOVED_TEMP ||
status == HttpURLConnection.HTTP_SEE_OTHER ||
status == 307 /* Temporary redirect */ ||
status == 308 /* Permanent redirect */)) {
if (++redirects > MAX_REDIRECTS)
throw new IOException("Too many redirects");
String header = urlConnection.getHeaderField("Location");
if (header == null)
throw new IOException("Location header missing");
String location = URLDecoder.decode(header, StandardCharsets.UTF_8.name());
url = new URL(url, location);
Log.i("Redirect #" + redirects + " to " + url);
urlConnection.disconnect();
continue;
}
if (status == HttpURLConnection.HTTP_NOT_FOUND)
throw new FileNotFoundException("Error " + status + ": " + urlConnection.getResponseMessage());
if (status != HttpURLConnection.HTTP_OK)
throw new IOException("Error " + status + ": " + urlConnection.getResponseMessage());
return urlConnection;
} catch (IOException ex) {
urlConnection.disconnect();
throw ex;
}
}
}
static Integer getLinkDownstreamBandwidthKbps(Context context) {
// 2G GSM ~14.4 Kbps
// G GPRS ~26.8 Kbps
// E EDGE ~108.8 Kbps
// 3G UMTS ~128 Kbps
// H HSPA ~3.6 Mbps
// H+ HSPA+ ~14.4 Mbps-23.0 Mbps
// 4G LTE ~50 Mbps
// 4G LTE-A ~500 Mbps
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
return null;
try {
ConnectivityManager cm = Helper.getSystemService(context, ConnectivityManager.class);
if (cm == null)
return null;
Network active = cm.getActiveNetwork();
if (active == null)
return null;
NetworkCapabilities caps = cm.getNetworkCapabilities(active);
if (caps == null)
return null;
return caps.getLinkDownstreamBandwidthKbps();
} catch (Throwable ex) {
Log.w(ex);
return null;
}
}
}